Air-pump



UNITED STATES PATENT OFFICE.

JOHN G. KENNEDY, OF DETROIT, MICHIGAN.

AIR-PUMP.

SPECIFICATION forming part of Letters Patent No. 409,844, dated August27, 1889.

' Application filed. February 11, 1889. Serial No. 299,485. (No model.)

To to whom it may concern:

I 3e 1t known that I, JOHN G. KENNEDY, a citizen of the United States,residing at Detroit, in the county of IVayne and State of Michigan, haveinvented certain new and useful Improvements in Air-Pumps, of which thefollowing is a specification, reference being had therein to theaccompanying drawings.

This invention relates to new and useful improvements in air-pumps, andthe in vention has especial reference to that class of air-pumpsprincipally designed to furnish compressed air for use in laboratoriesor for medical use, such as in apparatus for medicating air or forsimilar use.

The object of my invention is to construct an air-pump of this kind thatis especially adapted to be operated by high speed, whereby the motivepower of electricity as ob tained by the use of small electrical motorsbecomes available. Pumps of this kind as at present constructed are notwell adapted to be operated at high speed, and, if used in connectionwith electric motors, they soon become inoperative.

To this end my invention consists in an improved construction of variousparts, all as more fully hereinafter described, and shown in theaccompanying drawings, in which Figure l is a vertical central sectionthrough my improved air-pump. Fig. 2 is an enlarged section through thewrist-pin connection of the pump-rod. Fig. 3 is an enlarged verticalsection through the induction and eduction ports in the pump-head. Fig.4 is a detail elevation of one of the crankwheels.

A is a suitable base supporting the pump by means of two parallelstandards 15, secured thereon and perferably formed of metal.

G is the pump-cylinder, screw-threaded upon its end.

D and D are the respective heads, provided with sockets, by means ofwhich they are detachably secured to the pump-cylinder, the head D bymeans of a screw-thread and the head D by means of a set-screw orsetscrews.

E is a pivot-pin by means of which the pump is suspended from the top ofthe standards B. This pivot-pin is of steel and passes loosely through asolid portion of the headD of the pump in the axis thereof, and therebyforms an extended bearing on which the pump oscillates. Suitable washersa are interposed between the head and the standards, and a milledscrew-nut b secures the pivot-pin detachably in place.

The lower head D is cup-shaped to form a well 0 for containing alubricant.

The piston F is provided with a suit. ble air-tight packing and hassecured to it a downwardly projecting brush d, .adapted to dip into thelubricant contained in the lower head, and by contact transfers the sameto the inner walls of the pump-cylinder, from which it is distributed bythe motion of the piston.

G is the induction and II is the eduction valve in the pump-head D, andthese are arranged in as close proximity as possible to the top of thepump-chamber for the purpose of avoiding dead-air spaces. The valve-seatof the induction-valve is formed in the lower end of the bushing I,secured into the top of the head, and which is provided with a centralborein which the coil-spring e is confined by a projecting shoulder inthe lower end of the bushing and by an adjustable collar fupon thescrew-threaded valve-stem of the valve to hold the latter adjust-ably tothe seat. The valve-seat of the eductionvalve is formed at the lower endof the central bore of a bushing 1, secured in the top of the head D,and the head D is guided in its vertical motion by a suitable guidethrough which. the valvestem passes, or by a suitable spider on thevalve-stem.

J is a nipple secured over the top of the bushing I to form with itsupper end a suitable connection with aneduction-pipe or flexible tubeand forming with its lower end a well g, in which any lubricant liableto be carried up along the inner-wall bushing I may be dropped withoutto prevent it from passing into the eduction-pipe. The lower end of thepiston-rod K is provided with a cross-head L, in which the wrist-pin Mis loosely secured. This pin consists of a tubu- These are peripherallygeared. to enits connection with the piston-rod.

gage with the drive-pinion O and revolve upon the stub-shafts P, whichproject laterally from the standards A. Each stub-shaft is provided withthe head 77 and with the shankz'j, the portion i of which is smooth andon which the crank-wheels are j ourn aled. Between the portions ij is ashoulder is, which bears against the inner face of the standard, whilethe screw-threaded portion j passes through the standard and isdetachably secured thereto by means of the nut Z. The drive-pinion O ispreferably of steel and provided upon its ends with the bearings m, bymeans of which the pinion is journaled in bushings P ,Which are screwedinto the standards and preferably provided with milled heads Q. One ofthe standards m projects through its bushing a suitable distance topermit of coupling itin any suitable manner to the shaft R of theelectric motor, which is shown in dotted outlines in Fig. 1, or to anyother motive power in any way desired.

The advantages which I derive from my construction are that the parts,even if operated at very fast speed, are not liable to become detachedor loose, which in the ordinary construction of air-pumps is such afrequent source of annoyance if attempted to be run at high speed. Itthe parts in my pump shall become loose, they are arranged to be readilytightened, as they are secured by bolts provided with milled nuts. Allthe parts in the whole pump are also perfectly balanced at each side ofa central line, so that no detrimental side motion or strain is created,and should any part become worn out it can be readily removed orreplaced without dismounting the pump. i

The parts most liable to get out of order in the ordinary constructionsare the crank and This I have remedied by the special construction of acentral crank formed between the two gearwheels, to both of which thepower is applied from the same drive-pinion, so that they must operateas one,being furthermore firmlyyoked together by the tubular crank orwrist-pin and its clamping bo1t.

The power being applied peripherally to the crank-wheels, there are notroublesome bearings as in the use of a crankshaft to which the power isapplied, and the expedient of j ournalin g the crank-wheelsindependently of each other on stub-shafts provides for larger bearingsand also for readily changing the relative engagement of the crankwheels with the pinion in case the cogs should wear unequally. To thisend I provide in each crank-wheel a corresponding series of holespreferably three, either one of which may be used to receive the bolt 0for the wrist-pin. Thus, if the cogs of the crank- Wheel (or the cogs ofthe pinion) become worn at a certain spot the relative engagement of thecrank wheels and pinion may be changed to bring the wear upon otherparts The drive-pinion is preferably cut of steel with a steel pin forjournal-bearings, and the bushings in which it is journaled arepreferably made of fiber or phosphor-bronze.

The lower head of the pump-cylinder is made readily detachable from thecylinder for the purpose of filling it with the lubricant when needed.

WVhat I claim as my invention is 1. In an air-pump, the combination ofthe uprights B and the drive-pinion Q, journaled therein and connectedwith the actuatingshaft of a motor, of the crank-wheels N, engaging withsaid drive-pinion and journaled upon stub-shafts secured to the uprightsB, the wrist-pin M, clamped between these crankwheels, the reciprocatingpiston-rod K, provided with the cross-head L, engaging'with saidwrist-pin, and the oscillating cylinder 0, substantially as described.

2. The combination,with the cylinder C, of the reciprocating piston F,provided with the brush cl and the lower head D, forming the well 0 forthe reception of a lubricant, substantially as described.

3. The combination, with the head D, of the bushing I, provided with theeductionvalve H, and the nipple J, secured thereto and forming the wellg, substantially as described.

t. The combination of the standards B, the

drive-pinion O, the bushings Q, in which the pinion is journaled, thecrank-wheels N, engaging with the pinion, the stub-shai'ts P, providedwith the head h, the cylindrical portion 1', the shoulder 70, thescrew-threaded portion j, and the nuts Z, the wrist-pin M, theclamping-bolt 0, provided with the nut P, the reciprocating piston rodK, provided with the cross-head L, the cylinder 0, provided with theheads D and D, and the bolt E, detachably secured through the standardsA and head D and provided with the washers a, substantially asdescribed.

5. In an air-pump, the combination, with the oscillating cylinder andpiston, of the actuating crank-wheels N, the tubular wrist-pin M,secured between these crankwheels, the clamping-bolt 0, provided withthe nut P, securing the wrist pin between the crank- Wheels, and thepiston-rod K, provided with the cross-head L, loosely engaging with saidwrist-pin, substantially as described.

6. The combination, in an air-pump, of the two vertical standards, acylinder oscillatingly suspended between said standards, a reciprocatingpiston-rod provided at its lower end with a cross-head, two crank-wheelsperipherally geared and journaled upon stubshafts secured to thestandards, a wrist-pin carried between the two crank-wheels and engagingwith the cross-head of the piston, and a single drive-pinion j ournaledin the standards below said crank-wheels and engaging with both of them,substantially as described.

7. The combination, with the reciprocating piston of an oscillatingair-pump, of two actuating crank-wheels j ournaled upon opposite sidesof the piston and peripherally geared, In testimony whereof Iaffix mysignature, in a drive-pinion engaging therewith, 2L Wristpresence of twowitnesses, this 31st day of pin detachably secured between these emnk- Ja-uuary, 1889.

Wheels, and a series of corresponding adjust- JOHN G. KENNEDY. 5ing-holes in said crank-wheels for varying the Witnesses:

adjustment of the Wrist-pin, substantially as J. PAUL MAYER,

described. A. B. EATON.

